Billing Plan
When processing an order, instead of storing a single billing date, you can store a detailed billing plan with several billing dates in the sales document at item level

Periodic billing is often used for rental and service agreements, in order to bill the full amount periodically at certain dates

Milestone billing is often used in plant engineering and construction, in order to spread billing of the full amount over several dates within a bilking plan

Depending on the business transaction you are processing, the system will automatically propose one of the two billing plan types

Periodic Billing
Periodic billing can be used, for example, for transactions involving rental contracts

The contract data stored in the system can then be used as the basis for creating the billing plan

The start and end dates define the duration of the billing plan
If possible, they are taken from the contract data
If the duration is unlimited, you may decide not to set an end date
In this case, new dates can be extended to the horizon (the horizon specifies the number of settlement periods that are set in the billing plan)

You can create new dates either directly in the billing plan or by using the report RVFPLA01
You should schedule the report to run at regular intervals, because new dates are not complied automatically when you bill individual settlement periods

You can use the billing dates to determine when and how often billing is carried out, for example, on the first day or the last day of every month

Milestone Billing
During milestone billing, the total value to be billed is distributed among the individual dates according to certain rules

You can enter as many dates per billing plan as you require

Billing plan dates can be blocked for billing

Changes that occur (for example, to the amounts) after you have created certain milestone billing documents are distributed among the remaining bill plan dates
The amount remaining to be retro-billed for the billing documents already created is included in the final invoice

The system creates an entry in the billing index for each billing date
This means that you will find an entry in the billing index for this milestone billing at the time of the billing date specified
In this case, billing is carried out as order-related

When you create a billing document, the system updates the status of the billing plan dates

Dates that have already been billed can no longer be changed in the billing plan

You can display existing billing documents using the document flow

Billing Plan with Link to Milestone Billing
A typical example of milestone billing is the billing of projects in plant engineering and construction
Such projects often include a series of milestones, which represents the completion of various stages of a project

In the SAP system, milestones are stored in a network along with planned and actual project data
Milestones are assigned to the billing plan dates and blocked for billing until you confirm the milestone as completed

In a milestone billing plan, you can now control the following about a billing date
Whether it is a fixed date
Whether the billing date should be updated with the actual date of the milestone
Whether the billing date is updated with the actual date of the milestone, if production is completed before the planned billing date

Billing Rule
A billing rule can be created for each billing plan date
This rule defines how the value to be billed on a particular date is determined

This allows you to define, for example, whether a fixed amount or a percentage of the total amount is to be billed

The system can also determine whether the amount to be billed counts as a final invoice for which as yet unbilled dates must also be taken into account

Within pricing, condition records are created for special condition types, for which monthly prices can be defined (when dealing with rental costs, for example)
This allows the value to be billed month by month

Billing Plan Customizing
The billing plant type is determined from the document item category and the relevance for billing (billing relevance I means relevant for billing plan with order-related billing)

Date descriptions represent the text description for the corresponding billing dates in the billing plan, for example, 0003 for contract completion or 0005 for assembly
They are of no importance for control purposes

The date categories defined have a control function at billing date level
For example, they determine the following
Which billing rule is used to settle the date
Whether the billing date is a fixed date
Whether a billing block is set for this date

Date rules are required in the billing plan to define the start date and end date, as well as to determine the relevant billing dates (for example, two days before the end of the month)

The foundation of every date determination rule is a basis date to which a defined period is added

Differentiation of periodic billing and milestone billing with the relevant controlling parameters is carried out via the billing plant type

The date proposal is used exclusively for milestone billing
It determines a sequence of dates that are used as the reference for date determination during order processing

VA41 Logistics > Sales and Distribution > Sales > Contract > Create
Create Contract: Initial Screen > Enter
Create Service and Maintenance: Overview > Item > Billing Plan
Create Service and Maintenance > Billing Plan > Conditions
Display Item – Conditions > Condition Record > Calculation Type
Process Billing Due List
Maintain Billing Due List > Display Billing List
Maintain Billing Due List > Save
Display Contract > Item > Billing Plan > Bill Status

The item category determines whether the item is assigned to a periodic or milestone billing plan
For example, billing plan type 02 (periodic billing) is assigned to item category WVN (maintenance contract item)
The billing plan type (milestone billing), on the other hand, is assigned to item category TAO (milestone factor)

The date category is the relevant criterion for controlling at the settlement period level
This is where control parameters such as the billing rule, use of the billing block, and default billing type can be set

Sales and Distribution > Billing > Billing Plan > Define and Assign Date Categories
Choose Activity > Maintain Date Category for Billing Plan Type
Change View “Maintain Date Category for Billing Plan Type”: Overview > Details